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What Is DNS? And Should You Change Your DNS Server?

By Ammar Aslam · Updated September 29, 2026 · 3 min read
What Is DNS? And Should You Change Your DNS Server?

Every time you type a website name like google.com, your device needs to find its numeric address. That lookup is done by DNS, the Domain Name System, often called the internet's phone book.

How DNS works

  1. You type a website name.
  2. Your device asks a DNS server, "What's the address for this name?"
  3. The server replies with an IP address, such as 142.250.x.x.
  4. Your browser connects to that address.

This happens in milliseconds, usually using your internet provider's DNS servers by default.

Why change DNS?

  • Reliability: if your provider's DNS has problems, websites won't load even though the internet works.
  • Speed: some public DNS services respond faster, though the difference is often small.
  • Security: some DNS services block known malicious websites.
  • Family filtering: family DNS services block adult content.
  • Privacy: encrypted DNS hides lookups from your network.

Popular public DNS services

ServiceAddressesNotes
Cloudflare1.1.1.1 / 1.0.0.1Fast, privacy-focused
Cloudflare for Families1.1.1.3 / 1.0.0.3Blocks malware and adult content
Google Public DNS8.8.8.8 / 8.8.4.4Reliable
Quad99.9.9.9Blocks malicious domains

Change DNS on Android

Settings → Network & internet → Private DNS → enter a hostname like one.one.one.one or dns.google. This encrypts DNS on Wi-Fi and mobile data.

Change DNS on Windows 11

Settings → Network & internet → Wi-Fi (or Ethernet) → Hardware properties → DNS server assignment → Edit → Manual → turn on IPv4 → enter addresses. You can also turn on DNS over HTTPS.

Change DNS for the whole home

In your router's settings, look for DNS under WAN or Internet settings. Changing it here applies to every device on your Wi-Fi, useful for family filtering.

DNS in troubleshooting

If some websites don't load but others do, or you see "DNS_PROBE_FINISHED" errors, changing DNS or flushing the DNS cache (ipconfig /flushdns on Windows) often fixes it. See connected but no internet.

DNS explained with a phone book

Imagine calling a friend. You remember their name, but your phone needs their number. Your contacts app looks up the name and finds the number. DNS does the same for websites: you remember "google.com"; DNS finds the numeric IP address. If your contacts app broke, you couldn't call anyone even though your phone line works. That's exactly what happens when DNS fails: the internet works, but names can't be looked up, so websites won't open.

Using DNS to protect children

Family-friendly DNS services block adult and malicious websites for every device connected to your router:

  1. Log into your router (see router login guide).
  2. Find the DNS settings, often under WAN, Internet or DHCP settings.
  3. Enter a family DNS service's addresses, such as Cloudflare for Families (1.1.1.3 and 1.0.0.3).
  4. Save and restart devices.

This is a good first layer of protection, but it doesn't work on mobile data and can be bypassed by tech-savvy users. Combine it with device-level controls. See parental controls.

Common DNS error messages

  • DNS_PROBE_FINISHED_NXDOMAIN: the name couldn't be found; check spelling or try another DNS.
  • DNS server not responding: the DNS server is unreachable; restart the router or change DNS.
  • ERR_NAME_NOT_RESOLVED: similar lookup failure; flush DNS and try again.

Frequently asked questions

Is changing DNS safe?

Yes, with reputable providers. Avoid unknown DNS servers.

Will DNS make downloads faster?

No. DNS affects how fast connections start, not download speed.

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Ammar Aslam
Ammar writes clear, practical tech guides that help everyday users fix problems, stay safe online and get more from their devices.

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